1. Field of the Invention
The present invention relates to the separation of mixtures of tertiary butyl alcohol and tertiary butyl acetate by extractive distillation using a hydrocarbon such as n-decane as solvent.
2. Description of the Prior Art
Tertiary butyl acetate is an important chemical of commerce having wide utility, for example, as a solvent.
It is known to produce tertiary butyl acetate by reaction of acetic acid and isobutylene over a solid sulfonate group containing cation exchange resin. See, for example, U.S. Pat. No. 3,678,099 and references disclosed therein including U.S. Pat. Nos. 2,671,332, 3,031,495, 3,172,905 and 3,173,943.
A significant advance in this art is that described and claimed in copending application Ser. No. 08/816,704 filed Mar. 13, 1997, now abandoned, wherein the reaction between isobutylene and acetic acid is carried out in the presence of tertiary butyl alcohol as selectivity enhancing modifier. See also copending application Ser. No. 09/030,171 filed Feb. 25, 1998, now U.S. Pat. No. 6,018,076, wherein at least part of the selectivity enhancing tertiary butyl alcohol is formed in situ by addition of water to the reaction system.
There is produced in processes such as above described a mixture comprised of tertiary butyl alcohol and tertiary butyl acetate which cannot be resolved by ordinary distillation procedures.